The prior art comprises child-proof capsules in which the opening can be achieved only following a succession of co-ordinated movements which are difficult for a child below a certain age to perform.
These embodiments comprise an internal capsule, provided with means for connecting, normally of a screw-type, which enable the internal cap to be removably applied on a container, and an external cap which covers the internal cap when applied thereon. The external cap is constrained to the internal cap in such a way that there is freedom of rotation (a security situation known as child-proof) or solidarity of rotation with the internal cap according to distinct relative axial positions which the external cap can assume in relation to the internal cap. Child-proof capsules have existed for a considerable time in the prior art and on the market, which are provided with an easy-break security strip as proof of first opening, associated directly to the external cap of the capsule. One of the capsules is described in Italian patent IT 1.187.213 by the same applicant. This type of capsule, apart from requiring rather complex dies for its realisation, also exhibits the drawback of possible breakage of the easy-break ribs which keep the security strip joined to the external cap. Accidental pressure on the external cap, which can slide axially to activate the child-proof property, can also provoke a detachment of the security strip without the container being opened, or without there being any real intention to open the container.
There are other known types of child-proof capsule, which are however often assembled from a large number of individual pieces and therefore require the use of complex and expensive dies for their realisation.
The main aim in the manufacture of capsules in general, and in the realisation of the present capsule in particular, is to make realisation thereof ever-more economical, with embodiments that gradually reduce the number of separate pieces needed for their construction, using the simplest equipment possible, while not sacrificing working-life of the product and high productivity in its manufacture.
A further aim of the present invention is to provide a capsule of the child-proof kind which does not exhibit the risk of accidental breakage of the security strip. An advantage of the present invention is to provide a child-proof capsule made of only two parts.
This aim is achieved by the process of the invention, as it is characterised in the appended claims.
With reference to the figures of the drawings, 1 denotes a container with a mouth and a neck 2, which is closed by means of the child-proof capsule 3 of the invention, comprising an internal cap 4 with an internal thread 6 for screwing onto a corresponding thread 7 fashioned on the neck 2 of the container 1. An external cap 5 is applied on the internal cap 4.
In the position illustrated in the figures of the drawings, i.e. the child-proof safety condition, the external cap 5 is in a first position, in which it is free to rotate about the internal cap 4. This position is achievable depending on the relative axial positions of the external cap 5 and the internal cap 4—a position which is maintained by means 8 which elastically keep the external cap 5 raised with respect to the internal cap 4.
When pressure is exerted in the direction indicated by the arrow 13 on the external cap 5, the external cap 5 moves downwards into a second position, not illustrated, and an internal cogging 9 fashioned on the upper part of the internal surface of the external cap 5 meshes with an external cogging 10 fashioned on the upper external surface of the internal cap 4. In this second position no reciprocal rotation can be achieved between the external cap 5 and the internal cap 4; it is therefore possible, by pressing on the external cap 5, to unscrew or screw the internal cap 4 from or onto the neck 2 of the container 1. The above description is also true of other childproof capsules of known type, like those disclosed in EP-A-0 963 916, EP-A-0 127 943, U.S. Pat. No. 5,676,268, U.S. Pat. No. 6,372,167.
The capsule of the invention comprises a security strip 12 which is made in a single piece with the internal cap 4, as an appendix on the peripheral edge 4a thereof facing the container 1.
The security strip 12 exhibits an annular shape with a V-section. There are therefore two circumferences of the security strip 12: a first circumference 12a of which is connected in a connection zone, with the peripheral edge 4a of the internal cap 4; and a second circumference 12b of which is free and engages, when the capsule is mounted on the container 1, with an annular projection 15 which is fashioned on the outside of the neck 2 of the container 1.
The connection zone between the security strip 12 and the peripheral edge 4a of the capsule exhibits a plurality of circumferential cuts, not joined together, which occupy the whole connection zone between the strip 12 and the peripheral edge 4a of the capsule. The cuts 16 are in fact mechanical incisions in the connection zone between the peripheral edge 4a of the capsule and the security strip 12 and are separated by uncut zones 17, of a thickness comprised between 0.1 and 1.0 mm.
In this way in the connection zone between the peripheral edge 4a of the capsule and the security strip an easy-fracture line (or rather a circumference) is created, which will break when stressed as will be better described hereinafter, and thus cause a detachment of the strip 12 from the internal cap 4.
Manufacture of the internal cap 4 and the security strip 12 in a single piece, having the above-described characteristics, can be done by press-forming and subsequent mechanical operations, for example following the process described in Italian patent IT 1.292.751. To this end the internal cap 4 with connected security strip 12 is made of a pressable plastic material.
The internal capsule 4 and the security strip 12 as above-described could, however, be made using other processes.
The capsule of the invention further comprises an annular projection 18 which is fashioned on the internal upper part of the internal cap 4 and is coaxial to the internal cap 4. The annular projection 18 is arranged so as to interfere, when the capsule is mounted on the container 1, with the internal wall of the neck 2 of the container 1; in this way the annular projection 18 guarantees sealed closure of the container 1 when the capsule is mounted thereon. This means that it is not necessary to include a seal, which in known capsules is constituted by a small disc which realises a “top” seal on the mouth of the container, and which is generally inserted either as an individual piece or as a pressure-glued element on the upper internal wall of the internal cap 4. Thus with the present invention an even greater reduction in the number of pieces needed is achieved, with a reduction in manufacturing and work times, as the annular projection 18, differently to the “top” seal, can be fashioned directly during the press-forming stage of the internal cap 4. Obviously, however, a normal “top” seal disc can be used, although it calls for use of a further and separate element.
The capsule of the invention, provided with the annular projection 18, is made in two pieces only, which are assembled by pressing the internal cap 4 into the external cap 5. If a seal disc is to be added, it is inserted or afforded internally of the internal cap 4 before the internal cap 4 is press-inserted into the external cap 5.
As mentioned herein above, in the position of FIG. 1 the external cap 5 is free to rotate about the internal cap 4, since the coggings 9 and 10 are not enmeshed. By exerting a pressure in the direction indicated by the arrow 13 on the external cap 5, the external cap 5 is axially downwardly displaced and the cogging 9 enmeshes with the other cogging 10. In this situation, as all relative rotation between the internal cap 4 and the external cap 5 is now inhibited, by screwing or unscrewing the external cap 5 the internal cap 4 will screw onto or unscrew from the neck 2 of the container 1.
On first opening of the container 1, the raising of the internal cap 4 causes contrast between the second free circumference 12b of the security strip and the annular projection 15 on the outside of the neck 2 of the container 1, causing the uncut zones 17 to break and the detachment of the security strip from the internal cap 4, signifying that the container 1 has been opened.
As the security strip is solidly constrained to the internal cap 4, an accidental pressure, which is not intended to break open the container 1, causes no stress on the uncut zones 17 and therefore no accidental detachment of the security strip. The strip can only be detached from the internal cap 4 when, after the external cap 5 is lowered, there is a deliberate rotation thereof causing the internal capsule 4 to unscrew from the neck 2, i.e. when there is a deliberate intention to open the container 1.
Thus with the capsule of the invention the aim of preventing accidental detachment of the security strip is achieved; also attained is the aim of making a manufacturing economy during construction of the capsule, which is obtained thanks to a limited number of pieces constituting the capsule and to the possibility of obtaining these pieces directly through press-forming and with relatively simple dies, thanks to the special shape of the internal cap 4.